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String Theory

Tony

Penultimate Amazing
Tony
Joined
Mar 5, 2003
Messages
15,410
Can anyone knowledgeable about string theory put it in terms understandable by the non-physicist and layman?
 
Someone noticed that there were similarities between quantum equations and vibrating strings. Hey - maybe subatomic particles are strings!

No, that doesn't work.

Unless you increase the number of dimensions to four, then it seems to be OK. And when you do the math, you get a particle that is massless and behaves like gravity! Maybe this is just the thing to unite the four forces! Much excitement!

Wait wait wait - that doesn't work either. We need more dimensions, like ten. Maybe the universe has ten dimensions, and six of them are just curled up real small!

Different groups working on this same idea come up with three or four different, seemingly incompatible approaches, and the math is hellacious.

Someone else figures that if you increase the number of dimensions to eleven, those different approaches can be shown to be compatible with each other. Let's call this m-theory.

What can we predict with this? Well, you can crank on the math and with lots of assumptions, get something that looks like stuff already discovered. Does that work? No? Y'know, maybe we can't actually predict that the universe must be this way. String theory seems to be compatible with just about any set of physics. Maybe an infinite number of ways.

But really smart people are working real hard on it.

That's my take, anyway, after reading The Elegant Universe.
 
i haven't read it.. only watched it.


Tony

Combining General Relativity(big stuff)
with Quantum Physics(small stuff).

Currently we have two sets of rules.. that don't work together.
We can't have both of the two theories above.

Currently they both apply, it is our best bet as to how the world functions.. But they aren't compatible with each other.

Which means we can't work with black holes, or the big bang.

GR is about big and heavy things
QP is about small and light things.

Which one do you use for a small and heavy thing? (as in a black hole, or big bang?)

That is the problem.

String ( or rather M-Theory ) is a new way of looking at the universe.

M-Theory is NOT a theory... not yet.
Currently M-Theory is a philosophy.

I personally believe, and hope, that M-Theory will become a real theory. But for now... it just isn't there.

Think of it as a draft for a theory.

What darwin had in the first few days after he got his idea.

Anything more specific?

Sincerely
Tobias
 
TobiasTheCommie said:
i haven't read it.. only watched it.
Click to expand...

I'm reading it now. Or I was reading it the other day. Or I was trying to, but there were these brats in the waiting room and they were watching Power Rangers Space Force Delta and all I wanted to know was, "Who's watching you and what happened to Alpha through Gamma?"

I've also got Greene's The Fabric of the Cosmos but I want to finish The Elegant Universe first.
 
there is a really good pbs 3 hour mini series based on the book(with the author) really good.
 
I enjoyed the PBS series...after watching it, I even understood string theory, etc.

but I still can't explain it.
:(
 
TobiasTheCommie said:
there is a really good pbs 3 hour mini series based on the book(with the author) really good.
Click to expand...

Yeah, I watched that too. We have it on DVD. The problem with PBS is the half hour of commercials so when they'd break between hours, I'd fall asleep and miss the first twenty minutes or so of the next one.
 
Without a lot of study I doubt you will really understand string theory. At best you can be made to think you understand it.
 
From what I remember from reading the Elegant Universe, with ordinary Quantum Mechanics you can by increasing the energy of a particle (and thus its frequency and shorter wavelength) you can observe Space-Time at a smaller and smaller scale until you get to the point where you get infinities in your equation due to ground state fluctuations. Positing that particles are made out of strings effectivly "blurs space time" because when the strings get to higher energy their wavelength increases and you can't probe space at a smaller scale.

That might have been way off. Where is Tez?
 
TobiasTheCommie said:
i haven't read it.. only watched it.


Tony

Combining General Relativity(big stuff)
with Quantum Physics(small stuff).

Currently we have two sets of rules.. that don't work together.
We can't have both of the two theories above.

Currently they both apply, it is our best bet as to how the world functions.. But they aren't compatible with each other.

Which means we can't work with black holes, or the big bang.

GR is about big and heavy things
QP is about small and light things.

Which one do you use for a small and heavy thing? (as in a black hole, or big bang?)

That is the problem.

String ( or rather M-Theory ) is a new way of looking at the universe.

M-Theory is NOT a theory... not yet.
Currently M-Theory is a philosophy.

I personally believe, and hope, that M-Theory will become a real theory. But for now... it just isn't there.

Think of it as a draft for a theory.

What darwin had in the first few days after he got his idea.

Anything more specific?

Sincerely
Tobias
Click to expand...

What about the talk of many "dimensions" in string theory?

I thought the theory of relativity dealt with traveling at the speed of light/time slowing down?
 
Tony said:
What about the talk of many "dimensions" in string theory?

I thought the theory of relativity dealt with traveling at the speed of light/time slowing down?
Click to expand...

Nope.. nothing to do with traveling at the speed of light/time slowing down.

String theory have 10 dimensions.

M-Theory have 11 dimensions.

In M-Theory we have 3 (x,y,z) +1(time) = 4.

Thus 7 left we can't see.

Imagine looking at a power line from far far away. it only have one dimension(left, right).

Imagine you are an ant on the power line, now you have another dimension(clockwise counterclockwise).

From a distance you can't see the "around" dimension... because it is too small.


Imagine blowing an atom up to the size of the solar system.. Then those 7 dimensions left, would be about the size of a car.. or a tree. That is how small they are.

The strings move within those 7 dimensions, and acording to the form of those dimensions they have a specific frequency.
That frequency makes it into.. an electron, a photon, a gravitron.

Everything is made up of those strings.... everthing...

Their frequency desides what they do/are.

Their frequency is dictacted by the 7 dimensions(how they are formed).


Of course... i may remember something incorrectly. But.. That is how i remember it.


Sincerely
Tobias
 
Tony said:
*snip* I thought the theory of relativity dealt with traveling at the speed of light/time slowing down?
Click to expand...

Special Relativity states that time slows down the closer you get to the speed of light. If I remember correctly (and I beg forgiveness if this is wrong), quantum physics was developed to explain the inconsistencies in classical Newtonian physics, specifically at the atomic and sub-atomic level. I don't know a lot about string theory, nor do I think I'm smart enough to comprehend it, but isn't it an attempt to reconcile the two?

I'm reading "In Search of Schroedinger's Cat" at the moment. In addition to "The Elegant Universe", can anyone make recommendations for further reading?
 
Somewhere I remember hearing about one version of string theory that dealt with 19 dimensions. Anyone know about this?
 
Frinkiak7 said:
Special Relativity states that time slows down the closer you get to the speed of light. If I remember correctly (and I beg forgiveness if this is wrong), quantum physics was developed to explain the inconsistencies in classical Newtonian physics, specifically at the atomic and sub-atomic level. I don't know a lot about string theory, nor do I think I'm smart enough to comprehend it, but isn't it an attempt to reconcile the two?

I'm reading "In Search of Schroedinger's Cat" at the moment. In addition to "The Elegant Universe", can anyone make recommendations for further reading?
Click to expand...

Ooh, I've read that on too. I like it.

String theory is a contender for being "The Theory of Everything." In fact, I think it's the only contender right now. The trouble is that there's several versions of it.
 
The thing that hooked my interest into string theory was that, supposedly, when constraints were put in place to make sure a string moves with self consistantcy, General Relativity pops out.
 
It is important to note that string theory is a popular hypothesis but has not been "officially" accepted because it is impossible to directly or indirectly observe a string. At least for right now.

The calculations involved describe the universe very well but will remain nothing but interesting mathmatical constructs until someone can figure out a way to detect a string.

I remember that at the end of "The Elegant Universe", the author suggests possible observations that would lend credibility to the idea. Unfortunately, all are technologically impossible.
 
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